Photoperiodism

On A Blog Around The Clock, Bora Zivkovic shares a newly published paper which he co-authored with researchers inspired by his blog. Their team recorded the egg-laying cycle of birds in the wild, where clutch sizes must answer to nature and not the hungry stewardship of a poultry farmer. They discovered that Eastern Bluebirds lay eggs along the same S-shaped interval curve observed in domesticated birds, which is "not dependent on external factors like food and energy, but [on] a fine-honed system of interactions between two circadian clocks." On Not Exactly Rocket Science, Ed Yong…